5 Weird Garden Soil Amendments For A Healthier Vegetable Garden

When you’re getting your vegetable garden ready for planting, you may be wondering what you can do to improve the quality of your garden soil. You can never go wrong by using compost, but there are many other garden soil amendments to choose from in your local garden center.

Wondering what to add to soil for the vegetable garden?

All of these soil additives can be mixed into your soil or even added to your compost pile. Using these items in your garden might seem weird, but they offer many benefits for improving soil in vegetable gardens and are an effective way to add nutrients to garden soil.

5 Weird Garden Soil Amendments

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Ashes

If you’re using real, untreated wood in your fireplace or fire pit, you can add the ashes that remain after the fire goes out to your garden to improve your garden soil.

Generally, ashes are good for garden soil, but it very much depends on where the ashes come from. You should not use charcoal ashes in your garden as the charcoal is usually treated with chemicals and lighter fluid that are not good for your soil.

However, adding the ash from burned organic materials (like wood and leaves) adds a vital nutrient, potassium, to your garden soil. Ashes applied to the top of your soil can also deter pests for some crops.

To use ashes for soil improvement, you can simply sprinkle the ashes on top of your garden bed and work them in to about 4 inches depth. Make sure you keep them dry before you use them as the potassium will quickly wash away if the ash gets wet.

On a large scale, too much ash can raise the pH of your soil too high, so if you have a very large quantity of ash to add to your garden, make sure you check the pH of your soil first. Most veggies prefer a pH between 6 and 7, so if your soil is already 6.8 or higher, you should avoid using too much ash to amend your garden soil.

Biochar

Biochar is charcoal made from organic materials. This is not the same kind of charcoal we use in our backyard grills. Biochar is made by low temperature, slow burning of organic material like wood, bone, and manure.

It’s been used as a soil additive for many centuries and provides many benefits for vegetable gardens. It helps the soil retain nutrients and water reducing the amount of irrigation and fertilizer you need to use.

Like ashes, it can raise the pH of your soil, but the charcoal bits bind and fix minerals and nutrients in your garden soil. Learn more about using biochar in your garden.

Bone meal & Blood meal

They sound really disturbing, but both bone meal and blood meal are very healthy amendments to vegetable gardens.

Bone meal is made from animal bones ground into a powder (how to make your own). Bone meal is great for the vegetable garden because all the minerals within bones like calcium, magnesium, and phosphorous, are slowly broken down and released into your soil.

Similarly, blood meal is dried and powdered animal blood which is an excellent source of nitrogen for your garden. Too much nitrogen can burn your plants, so be careful using blood meal around young plants that are not nitrogen deficient.

How to use bone meal & blood meal for the vegetable garden:

Add bone meal up to 10 pounds per 100 square feet of garden

Sprinkle 1/4 -1/2 cup blood meal around nitrogen deficient plants or add to soil according to directions on the bag. (More info)

Be aware that bone and blood meal can be toxic to pets if ingested, so make sure you keep it out of their reach.

Greensand

Greensand is a marine sediment that is rich in potassium, iron, and other minerals. It looks like green colored sand and is sometimes called glauconite.

Greensand provides a slow release fertilizer and can be helpful for improving clay soil in your vegetable garden. Clay is inherently good at retaining nutrients and minerals in soil, but it doesn’t drain well.

So it makes sense to think sand can improve the drainage of clay. But you have to be careful adding sand to clay soil. In the wrong proportions, it can actually turn clay soil into something like concrete.

Sprinkle a cup or two around young plants to help warm the soil and retain nutrients and moisture.

Seaweed

Whether harvested fresh from the beach, composted, or dried and ground into a powder (sold as kelp meal), seaweed makes an excellent additive to soil adding nutrients as well as improving texture, water retention, and aeration in your garden.

Seaweed also encourages the growth of beneficial microbes and when used as a mulch can deter pests and pets from bothering your plants.

If you’re planning to harvest your own seaweed, make sure you check for any local restrictions. Deposits of seaweed above the tide line are important habitats for animals as well as controlling erosion.

Other things you can toss into your garden for healthier soil

If you’re looking for more tips on improving soil for your vegetable garden, here are some common things that you can add to your soil to improve texture, decrease weeds, and add nutrients:

Vegetable scraps: if you want to, skip the composting process and toss your scraps right into your garden. It’s best to dig a hole and bury them so you don’t attract pests.

Coffee: coffee grounds or liquid can add valuable nitrogen to your garden soil. Pour your leftover (cold) coffee into your garden or even on your houseplants for a boost of nutrients. Rake grounds into the surface of your garden soil so they don’t clump together.

Cardboard and newspaper: shredded or laid flat as mulch are excellent for preventing weeds and adding organic material. Plant right on top of them or till them in and let them decompose naturally.

Shells: eggshells and seashells can be added to your soil for slow release calcium

From the comments:

Hair: that’s a weird one for sure! Hair can be composted, or you can add hair to your vegetable garden. Both animal and human hair can be used in the garden. It will decompose over time releasing nitrogen and improving texure of the soil. (Thanks, Roxy!)

Dryer lint: Yes! You can add dryer lint to your garden. It can also be composted as ‘brown’ material. Dryer lint contains hairs and fibers from your clothes both of which can help improve texture and nutrients in the soil. (Thanks, Lorri!)

Duckweed: duckweed is a floating plant that thrives in slow moving water. Some homeowners find it to be a nuisance because it can quickly cover an entire pond. Turns out, it’s a great natural fertilizer for your garden (more info)! So if you have access to this plant, and permission to use it, go ahead and add it to your garden. (Thanks, Holly!)

I’ve added worm castings (worm poop) from a vermiculture box, and also duckweed, which is similar to seaweed, but it was the light green plant growing on top of a freshwater pond. The duckweed definitely helped the garden hold on to moisture and added nutrients! We could see exactly where it was added the garden thrived during a very hot summer.

Coffee grounds, by the way, should be well composted before adding to a garden bed.

Worm castings are full of nutrients and make a great soil additive! That’s a great tip about duckweed, too. Coffee grounds are great in compost, and in small quantities, are actually okay to add directly to the soil. A large amount (like a bucket full from a restaurant) could definitely cause problems for some plants, though. Thanks for pointing that out! 🙂